The book is freely available, though Butterick has a number of suggestions as to how you might recompense him for his effort.

If you’re vaguely interested in how your documents appear to others — and which lawyer would not be? — but are hesitant to invest much time in learning about typography, you’ll be glad to know that the book begins with a boast and a section offering to give you the essentials in a mere ten minutes. It can’t get much easier than that.